Some remarks:
1. MUSTFIX:
This spec doesn't apply $RPM_BUILD_ROOT. It compiles and places its files
directly into */BUILD.
One way to approach this:
%setup -c -T
2. Is there an agreement with the glibc developers upon using the name
libmalloc.*? To me, this name appears as too general.
3. http://mr.himki.net/index-alloc.html is in a Cyrillan written language
(Russian?). An English version would be helpful, because except of the source
code there doesn't seem to be any other documentation.
4. The source file seems to be intended to be used as a preloaded module:
From the source code:
* Compilation: gcc -shared -fPIC -O2 OpenBSD_malloc_Linux.c -o malloc.so
* Launching: LD_PRELOAD=/path/to/malloc.so firefox
I am not sure if packaging it as a library is a wise decision.

(In reply to comment #4)
> 1. MUSTFIX:
>
> This spec doesn't apply $RPM_BUILD_ROOT. It compiles and places its files
> directly into */BUILD.
>
> One way to approach this:
> %setup -c -T
Done.
>
> 2. Is there an agreement with the glibc developers upon using the name
> libmalloc.*? To me, this name appears as too general.
Renamed.
> 3. http://mr.himki.net/index-alloc.html109 is in a Cyrillan written language
> (Russian?). An English version would be helpful, because except of the source
> code there doesn't seem to be any other documentation.
OK, I'll try to add something more valuable docs.
> 4. The source file seems to be intended to be used as a preloaded module:
> I am not sure if packaging it as a library is a wise decision.
Hmmm. Are any recomendations about handling of preloaded libraries?
http://lemenkov.googlepages.com/openbsd-malloc.spechttp://lemenkov.googlepages.com/openbsd-malloc-0-4.src.rpm

Note that this built for me in mock on rawhide but did not install:
mock: /usr/bin/yum --installroot /mock/fedora-development-x86_64/root/ install
/mock/fedora-development-x86_64/result/openbsd-malloc-0-4.fc9.x86_64.rpm
/mock/fedora-development-x86_64/result/openbsd-malloc-debuginfo-0-4.fc9.x86_64.rpm
Error: Missing Dependency: ld-linux-x86-64.so.2(GLIBC_PRIVATE)(64bit) is needed
by package openbsd-malloc